581 update admin UI implementation to make meta functionality reusable

admin-ui/src/main/java/eu/knowledge/engine/admin/MetadataKB.java

@@ -0,0 +1,233 @@
+package eu.knowledge.engine.admin;
+
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.concurrent.ExecutionException;
+
+import org.apache.jena.rdf.model.Model;
+import org.apache.jena.rdf.model.Resource;
+import org.apache.jena.shared.PrefixMapping;
+import org.apache.jena.sparql.graph.PrefixMappingMem;
+import org.apache.jena.sparql.lang.arq.ParseException;
+import org.apache.jena.update.UpdateAction;
+import org.apache.jena.update.UpdateFactory;
+import org.apache.jena.update.UpdateRequest;
+import org.apache.jena.vocabulary.RDF;
+import org.eclipse.microprofile.config.ConfigProvider;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import eu.knowledge.engine.smartconnector.api.AskKnowledgeInteraction;
+import eu.knowledge.engine.smartconnector.api.BindingSet;
+import eu.knowledge.engine.smartconnector.api.CommunicativeAct;
+import eu.knowledge.engine.smartconnector.api.GraphPattern;
+import eu.knowledge.engine.smartconnector.api.ReactExchangeInfo;
+import eu.knowledge.engine.smartconnector.api.ReactKnowledgeInteraction;
+import eu.knowledge.engine.smartconnector.api.Vocab;
+import eu.knowledge.engine.smartconnector.util.KnowledgeBaseImpl;
+
+/**
+ * Knowledge Base that keeps track of all other KBs in the network. It does this
+ * by subscribing to meta knowledge interactions and updating its state
+ * accordingly.
+ *
+ * We use Apache Jena's API extensively to work with the results of our
+ * interactions.
+ *
+ */
+public class MetadataKB extends KnowledgeBaseImpl {
+
+	private static final Logger LOG = LoggerFactory.getLogger(MetadataKB.class);
+
+	private static final String META_GRAPH_PATTERN_STR = "?kb rdf:type ke:KnowledgeBase . ?kb ke:hasName ?name . ?kb ke:hasDescription ?description . ?kb ke:hasKnowledgeInteraction ?ki . ?ki rdf:type ?kiType . ?ki ke:isMeta ?isMeta . ?ki ke:hasCommunicativeAct ?act . ?act rdf:type ke:CommunicativeAct . ?act ke:hasRequirement ?req . ?act ke:hasSatisfaction ?sat . ?req rdf:type ?reqType . ?sat rdf:type ?satType . ?ki ke:hasGraphPattern ?gp . ?gp rdf:type ?patternType . ?gp ke:hasPattern ?pattern .";
+
+	private final PrefixMapping prefixes;
+
+	// used for getting initial knowledge about other KBs
+	private AskKnowledgeInteraction aKI;
+	// used triggered when new knowledge about other KBs is available
+	private ReactKnowledgeInteraction rKINew;
+	// used triggered when knowledge about other KBs changed
+	private ReactKnowledgeInteraction rKIChanged;
+	// used triggered when knowledge about other KBs is deleted
+	private ReactKnowledgeInteraction rKIRemoved;
+
+	private Model metadata;
+
+	private GraphPattern metaGraphPattern;
+
+	private boolean timeToSleepAndFetch = true;
+
+	/**
+	 * Intialize a MetadataKB that collects metadata about the available knowledge
+	 * bases.
+	 */
+	public MetadataKB(String id, String name, String description) {
+		super(id, name, description);
+
+		// store some predefined prefixes
+		this.prefixes = new PrefixMappingMem();
+		this.prefixes.setNsPrefixes(PrefixMapping.Standard);
+		this.prefixes.setNsPrefix("ke", Vocab.ONTO_URI);
+
+		this.metaGraphPattern = new GraphPattern(this.prefixes, META_GRAPH_PATTERN_STR);
+
+		// create the correct Knowledge Interactions
+		this.aKI = new AskKnowledgeInteraction(new CommunicativeAct(), this.metaGraphPattern, true);
+		this.rKINew = new ReactKnowledgeInteraction(
+				new CommunicativeAct(new HashSet<Resource>(Arrays.asList(Vocab.NEW_KNOWLEDGE_PURPOSE)),
+						new HashSet<Resource>(Arrays.asList(Vocab.INFORM_PURPOSE))),
+				this.metaGraphPattern, null);
+		this.rKIChanged = new ReactKnowledgeInteraction(
+				new CommunicativeAct(new HashSet<Resource>(Arrays.asList(Vocab.CHANGED_KNOWLEDGE_PURPOSE)),
+						new HashSet<Resource>(Arrays.asList(Vocab.INFORM_PURPOSE))),
+				this.metaGraphPattern, null);
+		this.rKIRemoved = new ReactKnowledgeInteraction(
+				new CommunicativeAct(new HashSet<Resource>(Arrays.asList(Vocab.REMOVED_KNOWLEDGE_PURPOSE)),
+						new HashSet<Resource>(Arrays.asList(Vocab.INFORM_PURPOSE))),
+				this.metaGraphPattern, null);
+
+		// register the knowledge interactions with the smart connector.
+		this.register(this.aKI);
+		this.register(this.rKINew, (rki, ei) -> this.handleNewKnowledgeBase(ei));
+		this.register(this.rKIChanged, (rki, ei) -> this.handleChangedKnowledgeBase(ei));
+		this.register(this.rKIRemoved, (rki, ei) -> this.handleRemovedKnowledgeBase(ei));
+
+	}
+
+	@Override
+	public void syncKIs() {
+		super.syncKIs();
+
+		if (timeToSleepAndFetch) {
+			// to receive the initial state, we do a single Ask (after sleeping for a
+			// specific amount of time)
+			try {
+				Thread.sleep(ConfigProvider.getConfig().getValue(AdminUIConfig.CONF_KEY_INITIAL_ADMIN_UI_DELAY,
+						Integer.class));
+			} catch (InterruptedException e) {
+				LOG.error("Initial metadata KB delay should not fail.", e);
+			}
+			this.fetchInitialData();
+			this.timeToSleepAndFetch = false;
+		}
+	}
+
+	public BindingSet handleNewKnowledgeBase(ReactExchangeInfo ei) {
+		if (!this.canReceiveUpdates())
+			return new BindingSet();
+
+		try {
+			Model model = eu.knowledge.engine.smartconnector.impl.Util.generateModel(this.aKI.getPattern(),
+					ei.getArgumentBindings());
+
+			Resource kb = model.listSubjectsWithProperty(RDF.type, Vocab.KNOWLEDGE_BASE).next();
+			this.metadata.add(model);
+			LOG.debug("Modified metadata with new KB '{}'.", kb);
+		} catch (ParseException e) {
+			LOG.error("{}", e);
+		}
+		return new BindingSet();
+	}
+
+	public BindingSet handleChangedKnowledgeBase(ReactExchangeInfo ei) {
+
+		if (!this.canReceiveUpdates())
+			return new BindingSet();
+
+		try {
+			Model model = eu.knowledge.engine.smartconnector.impl.Util.generateModel(this.aKI.getPattern(),
+					ei.getArgumentBindings());
+
+			// this is a little more complex... we have to:
+			// - extract the knowledge base that this message is about
+			// - delete all old data about that knowledge base
+			// - insert the *new* data about that knowledge base
+
+			Resource kb = model.listSubjectsWithProperty(RDF.type, Vocab.KNOWLEDGE_BASE).next();
+			String query = String.format("DELETE { %s } WHERE { %s FILTER (?kb = <%s>) } ",
+					this.metaGraphPattern.getPattern(), this.metaGraphPattern.getPattern(), kb.toString());
+
+			UpdateRequest updateRequest = UpdateFactory.create(query);
+			UpdateAction.execute(updateRequest, this.metadata);
+
+			this.metadata.add(model);
+
+			LOG.debug("Modified metadata with changed KB '{}'.", kb);
+
+		} catch (ParseException e) {
+			LOG.error("{}", e);
+		}
+		return new BindingSet();
+	}
+
+	public BindingSet handleRemovedKnowledgeBase(ReactExchangeInfo ei) {
+		if (!this.canReceiveUpdates())
+			return new BindingSet();
+
+		try {
+			Model model = eu.knowledge.engine.smartconnector.impl.Util.generateModel(this.aKI.getPattern(),
+					ei.getArgumentBindings());
+
+			// this is also a little complex... we have to:
+			// - extract the knowledge base that this message is about
+			// - delete all old data about that knowledge base
+
+			Resource kb = model.listSubjectsWithProperty(RDF.type, Vocab.KNOWLEDGE_BASE).next();
+			String query = String.format("DELETE { %s } WHERE { %s FILTER (?kb = <%s>) } ",
+					this.metaGraphPattern.getPattern(), this.metaGraphPattern.getPattern(), kb.toString());
+
+			UpdateRequest updateRequest = UpdateFactory.create(query);
+			UpdateAction.execute(updateRequest, this.metadata);
+
+			LOG.debug("Modified metadata with deleted KB '{}'.", kb);
+
+		} catch (ParseException e) {
+			LOG.error("{}", e);
+		}
+		return new BindingSet();
+	}
+
+	public void fetchInitialData() {
+		LOG.info("Retrieving initial other Knowledge Base info...");
+
+		try {
+
+			// execute actual *ask* and use previously defined Knowledge Interaction.
+			this.getSC().ask(this.aKI, new BindingSet()).thenAccept(askResult -> {
+				try {
+					// using the BindingSet#generateModel() helper method, we can combine the graph
+					// pattern and the bindings for its variables into a valid RDF Model.
+					this.metadata = eu.knowledge.engine.smartconnector.impl.Util.generateModel(this.aKI.getPattern(),
+							askResult.getBindings());
+					this.metadata.setNsPrefixes(this.prefixes);
+
+				} catch (ParseException e) {
+					LOG.error("{}", e);
+				}
+			}).handle((r, e) -> {
+				if (r == null && e != null) {
+					LOG.error("An exception has occured while retrieving other Knowledge Bases info", e);
+					return null;
+				} else {
+					return r;
+				}
+			}).get();
+		} catch (ExecutionException | InterruptedException ee) {
+			LOG.error("{}", ee);
+		}
+
+	}
+
+	protected boolean canReceiveUpdates() {
+		return this.metadata != null;
+	}
+
+	public void close() {
+		this.stop();
+	}
+
+	public Model getMetadata() {
+		return metadata;
+	}
+}

admin-ui/src/main/java/eu/knowledge/engine/admin/api/RestServer.java

@@ -1,8 +1,5 @@
 package eu.knowledge.engine.admin.api;
 
-import eu.knowledge.engine.admin.AdminUI;
-import eu.knowledge.engine.rest.api.CORSFilter;
-
 import org.eclipse.jetty.server.Server;
 import org.eclipse.jetty.servlet.ServletContextHandler;
 import org.eclipse.jetty.servlet.ServletHolder;
@@ -12,6 +9,9 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import eu.knowledge.engine.admin.AdminUI;
+import eu.knowledge.engine.rest.api.CORSFilter;
+
 public class RestServer {
 
 	private static final Logger LOG = LoggerFactory.getLogger(RestServer.class);
@@ -45,7 +45,7 @@ public static void main(String[] args) {
 		ServletContainer scRuntime = new ServletContainer(rcRuntime);
 		ServletHolder jerseyRuntimeServlet = new ServletHolder(scRuntime);
 		ctx.addServlet(jerseyRuntimeServlet, "/runtime/*");
-		
+
 		ResourceConfig rcAdmin = new ResourceConfig();
 		rcAdmin.property(ServerProperties.BV_SEND_ERROR_IN_RESPONSE, true);
 		rcAdmin.property(ServerProperties.WADL_FEATURE_DISABLE, true);

admin-ui/src/main/java/eu/knowledge/engine/admin/api/impl/AdminApiServiceImpl.java

@@ -15,6 +15,7 @@
 import org.slf4j.LoggerFactory;
 
 import eu.knowledge.engine.admin.AdminUI;
+import eu.knowledge.engine.admin.MetadataKB;
 import eu.knowledge.engine.admin.Util;
 import eu.knowledge.engine.admin.model.AnswerKnowledgeInteraction;
 import eu.knowledge.engine.admin.model.AskKnowledgeInteraction;
@@ -91,7 +92,7 @@ public void getSCOverview(
 			@Suspended final AsyncResponse asyncResponse, @Context SecurityContext securityContext)
 			throws NotFoundException {
 		admin = AdminUI.newInstance(false);
-		model = this.admin.getModel(); // todo: needs locking for multi-threading? Read while write is busy.
+		model = this.admin.getMetadata(); // todo: needs locking for multi-threading? Read while write is busy.
 		if (model != null && !model.isEmpty()) {
 			Set<Resource> kbs = Util.getKnowledgeBaseURIs(model);
 			SmartConnector[] responses = findAndAddConnections(convertToModel(kbs, model, includeMeta));

admin-ui/src/test/java/eu/knowledge/engine/admin/api/TestApiRoutes.java

@@ -1,19 +1,9 @@
 package eu.knowledge.engine.admin.api;
 
-import com.fasterxml.jackson.databind.ObjectMapper;
-
-import eu.knowledge.engine.admin.AdminUI;
-import eu.knowledge.engine.smartconnector.api.*;
-import eu.knowledge.engine.smartconnector.util.MockedKnowledgeBase;
-
-import org.apache.jena.shared.PrefixMapping;
-import org.apache.jena.sparql.graph.PrefixMappingMem;
-import org.junit.jupiter.api.AfterAll;
-import org.junit.jupiter.api.BeforeAll;
-import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.TestInstance;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.fail;
 
 import java.io.IOException;
 import java.io.OutputStream;
@@ -29,15 +19,35 @@
 import java.util.Collections;
 import java.util.concurrent.CountDownLatch;
 
-import static org.junit.jupiter.api.Assertions.*;
+import org.apache.jena.shared.PrefixMapping;
+import org.apache.jena.sparql.graph.PrefixMappingMem;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.TestInstance;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import eu.knowledge.engine.admin.AdminUI;
+import eu.knowledge.engine.smartconnector.api.AnswerHandler;
+import eu.knowledge.engine.smartconnector.api.AnswerKnowledgeInteraction;
+import eu.knowledge.engine.smartconnector.api.AskKnowledgeInteraction;
+import eu.knowledge.engine.smartconnector.api.Binding;
+import eu.knowledge.engine.smartconnector.api.BindingSet;
+import eu.knowledge.engine.smartconnector.api.CommunicativeAct;
+import eu.knowledge.engine.smartconnector.api.GraphPattern;
+import eu.knowledge.engine.smartconnector.api.SmartConnector;
+import eu.knowledge.engine.smartconnector.util.KnowledgeBaseImpl;
 
 @TestInstance(TestInstance.Lifecycle.PER_CLASS)
 public class TestApiRoutes {
 	private Thread thread;
 	private static final Logger LOG = LoggerFactory.getLogger(TestApiRoutes.class);
 
-	private static MockedKnowledgeBase kb1;
-	private static MockedKnowledgeBase kb2;
+	private static KnowledgeBaseImpl kb1;
+	private static KnowledgeBaseImpl kb2;
 
 	private static AdminUI admin;
 	private HttpClient httpClient;
@@ -242,7 +252,7 @@ public void startKbs() throws InterruptedException {
 		int wait = 2;
 		final CountDownLatch kb2ReceivedData = new CountDownLatch(1);
 
-		kb1 = new MockedKnowledgeBase("kb1") {
+		kb1 = new KnowledgeBaseImpl("kb1") {
 			@Override
 			public void smartConnectorReady(SmartConnector aSC) {
 				LOG.info("smartConnector of {} ready.", this.name);
@@ -269,7 +279,7 @@ public void smartConnectorReady(SmartConnector aSC) {
 		// todo: ask/poll if ready instead of waiting
 		Thread.sleep(5000);
 		kb2 = null;
-		kb2 = new MockedKnowledgeBase("kb2") {
+		kb2 = new KnowledgeBaseImpl("kb2") {
 			@Override
 			public void smartConnectorReady(SmartConnector aSC) {
 				LOG.info("smartConnector of {} ready.", this.name);
@@ -294,7 +304,7 @@ public void stopKbs() {
 		stopKb(kb2);
 	}
 
-	public void stopKb(MockedKnowledgeBase aKb) {
+	public void stopKb(KnowledgeBaseImpl aKb) {
 		if (aKb != null) {
 			aKb.stop();
 		}